The invention is directed to sensing the flow of a fluid in a conduit and or particulary to sensing the flow of liquid in a conduit and utilizing that sensing to operate external devices.
It is important to know whether or not a fluid is flowing and flowing sufficiently in a conduit which is either remotely located, is not transparent or is not constantly monitored or observed so that the fluid flow therethrough is not readily apparent to the observer.
There are several areas of concern where a constant flow of fluid is a very vital, important and necessary requirement to the continuing operation of certain devices. An example of these devices are internal combustion engines where the absence of cooling fluid results in their failure and destruction; Pumps where the fluid being pumped also acts as the cooling medium or the lack of a fluid flow results in a run-away condition which could destroy the pump; and any fluid transfer where knowledge that the transfer is in process is desired.
In my prior U.S. Pat. Nos. 4,524,736 and 4,615,303 devices are claimed the detect the flow in a conduit wherein a second conduit is positioned within a first conduit through which a fluid flows. The features in these patents are very effective in performing the functions to which they are directed; However, the features of the present invention perform equally as well as the referenced patents and the specific embodiments of the present invention require less operating components which reduce the possibility of encountering operational failure.